THE EFFECT OF PVD COATING ON ROLLING CONTACT FATIGUE OF SINTERED MATERIAL

Abstract

Paper describes changing properties of the coated samples according to the contact fatigue as a specific phenomenon causing damage to the surface of stressed materials by cyclical stress changes and the emergence of so-called piting on the surface. The aim of the work is to explore the impact of using TiN and CrN PVD coatings to extend the life of sintered materials, which are currently widely replacing traditional materials compact also in highly stressed applications. For coating was used sintered material Astaloy CrL with 0.3% C and TiN coating and also material Astaloy CrL + 0.7% C coated with CrN. Roling contact fatigue was assessed on the device type Axmat according to service life up to 50.10^6 cycles. The test results were evaluated in the form of S-N curves and further described by Metalographic-microscopic analysis as well as by the respective mechanical tests.